PROCESS FOR THE PREPARATION OF L-CARNITINE

摘要

PURPOSE: Provided is a method for manufacturing high-purity L-carnitine in a high yield through one-pot reaction using cheap compounds and reducing the use of organic solvents, which does not require any purification process. CONSTITUTION: L-carnitine is manufactured by: i) ring-opening reaction of (S)-3-activated hydroxybutyrolactone of the formula (2) in the presence of acid as catalyst and solvent to manufacture 4-hydroxy-3-activated hydroxybutyric acid of the formula (3); ii) reverse-conversion of the chiral center of 4-hydroxy-3-activated hydroxybutyric acid of the formula (3) in the presence of base to manufacture salt of 3,4-epoxybutyric acid of the formula (4); and iii) nucleophilic substitution of the salt of 3,4-epoxybutyric acid of the formula (4) with trimethylamine to manufacture L-carnitine of the formula (1). In the formula, R is alkylsulfonyl, arylsulfonyl, acyl group or phosphate. M is determined by the used base.